Current Research

My current research is focused on the sources, chemistry, transport and air quality impacts of reactive nitrogen oxide compounds (NOy) and ozone in the troposphere. Reactive nitrogen oxide compounds include NO and NO2 (collectively termed NOx) that are primarily sourced from combustion, both anthropogenic and natural (e.g., wildfires), as well as HNO3, PAN, HONO, N2O5, and a variety of organic nitrates. NOx, in conjunction with volatile organic compounds, is the primary source of tropospheric ozone, a secondary air pollutant that is commonly an air quality concern for heavily-populated, urban areas. To study these compounds, I conduct airborne measurements of NO, NO2, NOy and O3 on board instrumented research aircraft (NOAA P-3 and NASA DC-8) with a chemiluminescence instrument built in our laboratory at NOAA.

Currently, I am involved in the on-going NASA Atmospheric Tomography (ATom) Mission. This project aims to conduct global-scale measurements of a large suite of reactive gases, greenhouse gases, and aerosols in the remote "background" atmosphere to study the chemistry and transport of human-caused and natural pollution. This project uses the NASA DC-8 Airborne Science Laboratory to interrogate the atmosphere between the north and south poles, from altitudes between 500 - 40,000 ft, over the Pacific, Atlantic, Arctic, and Southern Oceans. Over 3 years, we will perform 4 complete global circuits to study seasonal differences between summer, winter, spring, and fall.The observations from this project will be vital for testing and improving our understanding of chemistry and transport that is represented in global chemistry-climate and chemistry-transport models (CCMs and CTMs). More information on this project can be found at: https://espo.nasa.gov/atom